Jet direction control device



Feb. 5 1957 w. A. FIEDLER 2,780,059

JET DIRECTION CONTROL DEVICE Filed Nov. 29, 1955 3 Sheets-Sheet 2 INVENTOR WI LLY A. Fl ED'LER AGTORNIS Fig.4

Feb. 5, 1957 w. A. FIEDLER JET DIRECTION CONTROL DEVICE 3 Sheets-Sheet 3 Filed Nov. 29, 1955 INVENTOR.v WILLY A. FIEDLER United States The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental puiposes without the pay ment of any royalties thereon "or therefor.

The present invention relates to a. jet direction control device for use in conjunction with 'jet propelled aircraft a'nd'more particularly to a jet direction control device utilizing a. movably mounted control member which may be selectively moved into the gaseous jet issuing from a discharge nozzle thereby deflecting the jet and changing the direction of thrust thereof to effectively alter the di- "rection of flight of the aircraft.

Similar dc ices for steeringaircra'ft' are known in the art as shown for example in U. 8. Patent #2,472,839. Such directional control means are adapted for use either in piloted aircraft or guided missiles wherein the propulsive force is provided by a gaseous jet issuing from a discharge nozzle at therear of the aircraft, the jetb'eiag produced either by conventional jet"aircraft engines or rocket engines.

Since the advent of supersonic'aircraft, the problem of controlling the direction of aircraft has become increasingly diflicult due to the large forces required to operate conventional aircraft controls such as elevators, ailerons, etc. One possible solutionto the problem is the elimination of conventional aircraft controls and theprovision of jet controls wherein thedirection of thrust of the jet is suitably altered'to change the course of the aircraft.

Prior devices such as shown for example in U. S. Patcub-#1472339 have the disadvantage of producing excessive drag on the aircraft due to the fact that the jet control men-fiber is mounted eXteriorly of the aircraft such that the air stream impingeson the control member. Additionally, relatively large forces are required to operate a controlfmember having a configuration such as shown in theaforeL tiorled patent wherein large hinge moments are develo d about the pivotpoint of he con-- tr'ol member mounting means. As consequence of tlle relatively large forces required to operate such devices, an additional conduit is extended from the fuselage to provide an auxiliary jct having a considerably smaller discharge area than'the main jet and accordingly creating less resistance toac' ion of the device. It is obvious that the provision of lch a conduit projecting laterally from the fuselage creates additional undesirable dragon the aircraft.

in order to effec ively control the direction of the aircraft, it is nece" to provide considerable deflection of the jet issuin the di ge nozzle, and this result is not obtainable ina device such as shown in the aforementioned patent wherein the pivotal movement of the jet control member severely limited since the leading edge thereof engages the outer wall of the conduit on which it is mounted after only a small a placement from the neutral position. For lermo're, should afailure occur in the actuating mechanism for the-jet control member, there is-no'provision'cf a positi've safety 'means WhlCh"Wi11 return the control member Y Z ,780,059 Patented @Feb. '5 1957 ice 2 to the neutral position. As a result, it is possible for the jet control to oscillate back and forth in the jet causing erratic and uncontrolled movements of the aircraft such that it may be directed far off the desired course.

The present inventionprovides an arrangement wherein the jet control is positioned about themain discharge nozzle of the aircraft thereby eliminating the necessity of an auxiliary conduit and discharge nozzle. cavity is provided in the fuselage of the aircraft fol-enclosing the jet control means such that the outer'surface of the fuselage forms a smooth contour and the'air stream does not impinge upon. the control means, thereby considerably reducing the drag on the aircraft. The cavity is also :provided with such a configuration as to permit pivotingof the control means through a large angle, and atthe same time this configuration reverses the induced gas flow within the cavity which is produced during operation of the device. The diametrically inner portion of the trailing edge of the so called jetevator control member is also beveled to provide a force thereon which normally biases the control member into neutral position such that upon failure of the actuating means for the jetevator control means, the invention device will not thereafter alter the course of the aircraft.

An object of the present invention is the provision of a new and novel jet direction controIl-devicewhich reduces the drag of-the device to a'lninirnum.

Another cbject is toprovidea jet direction control device which provides a safety feature wherein upon flailure of theactuating means for the device, the control means will automatically return to the neutrabposition.

A further object of the invention is the provision-of a jet direction control device which issimple and inexpensive in construction yet sturdy and reliable'in operation.

Other objects and manyof the attendant-advantages of. this invention will be readily appreciated aslthe same becomes better understood by reference tothe followingldetailed description when considered in connection with the accompanying drawings wherein:

Fig. l is a longitudinal section'of the present invention;

Fig. 2 isa View similar to Fig. l illustrating a modificatiou thereof; I

Fig. 3 is an elevation, partially in section; of a modification of the present invention;

Fig. 4 is an end View of the device shown inFig. 3-; and

Fig. 5 is a vertical section takenalong line V-V-in Fig. '2.

Referring now to the drawings wherein like reference characters designate like or corresponding partslthrougb out the several views, there is shown in Fig. l-ajbody means 10 which represents therearportion of the' fuselage of an aircraft such as'a piloted airplaneor. guided missile which is propelled by-a conventional jet engine or rocket motor. The rear portion of the body means is hollow and is provided witha conventional diverging nozzle 11 adapted to exhaust and' expand-a gaseous jet to provide propulsive force for the aircraft, the-body means and the nozzle being formed symmetricallyabout a longitudinal axis X--X. The body means is substantially cylindricalin configuration and'the rear end portion 12 thereof is provided with an annular -cavity"13 surrounding nozzle 11 and defining a'discharge end -portion 14 between the cavity and the interiorof the-nozzle,

portion 14 extending rearwardly of portion 12.

Discharge end portion 14 has asubstantially cylindrical shoulder 15 formed thereon which supports two dia- 'metrically opposite pivot pins 16 secured thereo. Each of pins '16 supports a conventional roller bearing 17 which in'turnsupports the jetevator control member 18 which isjsubsta'ntiallyannular in configuration. .t l

Jetevator member 18 hasa'ljeading edg '25 and a trailtially cylindrical and the inner surface 28 thereof defining a segment of a sphere. It is evident that jetevator control member 18 is adapted to be pivoted about pins 16 and any desired actuating means (not shown) may be provided for operating member 18 through the medium of a suitable linkage connected to the leading edge of the control member at a point displaced 9() degrees from pins 16.

Control member 18 is shown in neutral position wherein it will have no effect upon the gaseous jet issuing from the nozzle 11. As control member 18 is pivoted about pin 16, it will move progressively into the jet stream causing larger and larger deflections of the jet which will alter the direction of the thrust thereof and change the direction of movement of the aircraft.

It is apparent that in the neutral position shown, the trailing edge of control member 18 is positioned closely adjacent the outer edge of discharge end portion 14 and that a small clearance is provided between the outer edge of portion 14 and the inner surface 28 of the control member. Such clearance is necessary since during operation, heat will cause the metallic member 18 and portion 14 to expand; and consequently it is not possible to have these members in contact with one another at all times. It should be noted, however, that it is desirable to maintain the inner surface 28 as near to the outer edge of portion 14 as possible during operation.

It is obvious that upon pivotal movement of control member 18, half of annular member 18 will be pivoted in a rearward direction and the other half will be pivoted in a forward direction. Cavity 13 is so constructed as to provide maximum deflection of control member 18 such that the forwardly pivoting portion of the control member is allowed to move forwardly and downwardly to a point abutting the outer wall of the nozzle portion.

The forward portion of control member 18 is disposed within catvity 13 when in neutral position thereby preventing any entrainment of air from the atmosphere and reducing the drag created by the device since the fuselage of the aircraft terminates in a smooth contour. During operation, however, when control member 18 is pivoted into the jet stream, a gaseous flow will be induced between the outer surface of portion 14 and the inner surface 28 of the control member from the jet into cavity 13. If such induced gas flow were merely allowed to escape in a direction normal to axis XX or to circulate in a random manner within chamber 13, the energy of the induced gas flow would be uselessly dissipated. In order to obtain a useful reaction in the forward direction of motion of the aircraft, the cavity is so shaped as to have a cross-sectional configuration as shown in Fig. 1 wherein the inner wall thereof has arcuately shaped portions as indicated at 30 and 31 such that the induced gas flow is deflected to follow a path indicated by arrows 32 and 33. The arcuate walls of the cavity thereby efliciently absorb the energy of the induced gas flow in much the same manner as the turbine blades in a steam turbine, reversing the gas flow within the cavity and creating a reaction force assisting the main jet in propelling the aircraft in a forward direction.

Due to the pivotal mounting of control member 18 and the spherical configuration of inner surface 28 thereof, no hinge moments are developed about pivot pin 16 and it is therefore quite easy to operate the jetevator control. When the jetevator control has been moved into the jet stream however, it will tend to remain in such position should the actuating means therefor fail during operation. Furthermore, if the actuating means fails, there is a danger that the control member will oscillate into and out of the jet stream causing erratic motions of the aircraft. To overcome this difficulty, the diametrically inner portion of trailing edge 26 is beveled to provide an oblique surface 29 which when acted upon by the jet stream creates a force on the control member biasing it to neutral position as shown in Fig. 1 of the drawing. It should be noted that when in neutral position, the beveled surface 29 is aligned with the rearward portion of the interior of nozzle 11 to simplify alignment of the nozzle and the control member. The hinge moment developed by surface 29 must be positive for safety considerations and should be small to minimize the size of the actuator required for the control member.

Fig. 2 illustrates a modification of the device shown in Fig. 1 wherein control member 18 is pivotally mounted upon an annular shaped ring member 35 in the same manner in which it was mounted upon portion 14 in Fig. 1. As shown in Fig. 5, the ring member is also pivotally mounted on two diametrically opposite pivot pins which are secured to discharge inner portion 14 at points displaced 90 degrees from the pivot pins supporting the control member on the ring member. With such a gimbal arrangement, control member 18 may be pivoted in a universal manner and suitable control means (not shown) may be provided for actuating the control member and the ring in a manner similar to that disclosed for actuating the corresponding members in U. S. Patent #2,472,839. The remaining structure of the device shown in Fig. 2 is identical with that shown in Fig. 1.

Fig. 3 illustrates a modification of the device wherein body means 19 and the components thereof are similar to those shown in Fig. 1 and which utilizes a different type of control member. In place of the unitary annular shaped control ring utilized in Fig. l, the device shown in Fig. 3 employs a control member comprising two arcuately shaped members 40 and 41 connected for simultaneous pivotal movement and being disposed at an angle to one another as most clearly seen in Fig. 3 whereby the trailing edges of members 40 and 41 are disposed adjacent the rear end of discharge portion 14 when in neutral position.

Control members 40 and 41 have the configuration of a catenary whereby the members may be made extremely light and yet have sufficient strength to withstand the forces applied by the jet stream due to the fact that all loads produced by the jet stream on members 40 and 41 are in tension. Since members having the configuration of a catenary have maximum strength to resist forces applied in tension, such a construction is ideal when it is desired to eliminate bulk and weight. It should be noted that the device shown in Figs. 3 and 4 has been turned 90 degrees from the position shown in Fig. 1 such that the pivot pins 16' are viewed from the top thereof in Fig. 3 rather than from the side as in Fig. 1. An opening 42 is also formed radially through rear end portion 12 to permit installation of pivot pins 16. It is evident that the control member as shown in Figs. 3 and 4 may also be mounted upon a gimbal arrangement such as shown in Fig. 2.

It is apparent from the foregoing that there is provided a new and novel jet direction control device which reduces drag to a minimum and provides a safety feature whereby the direction control means is automatically biased into neutral position due to forces generated by the gaseous jet. The device is simple and inexpensive in construction, yet is sturdy and reliable in operation.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A jet direction control device which comprises an elongated body means including a discharge end portion having a nozzle opening formed therein symmetrically about a longitudinal axis and adapted to exhaust a gaseous jet therefrom, a control means movably supported by said body means, said control means substantially surrounding said end portion and being symmetrical about said axis when in neutral position, said control means having a leading edge and a trailing edge, means for moving a portion of said trailing edge toward said axis, said body means having a rear end portion adjacent said discharge end portion and extending diametrically outward of said discharge end portion, said rear end portion having an annular cavity formed therein which opens toward the rear of said body means, the forward portion of said control means being disposed within said cavity when the control means is in neutral position, said cavity having an arcuate surface for reversing the gaseous flow induced between the outer surface of said discharge end portion and the inner surface of said control means during operation of the device.

2. A device as defined in claim 1 wherein the diametrically inner portion of said trailing edge is beveled whereby a gaseous jet issuing from said nozzle produces a force tending to bias said control means into neutral position.

3. A jet direction control device which comprises a body means including a discharge end portion having a nozzle opening formed therein and adapted to exhaust a gaseous jet therefrom, a control means pivotally supported by said body means and substantially surrounding said end portion, said control means having a leading edge and a trailing edge, said trailing edge being positioned closely adjacent the outer end of said discharge end portion and forming substantially no obstruction to a jet issuing from said nozzle when the control means is in neutral position, means for pivoting said control means out of neutral position, said body means having a rear end portion adjacent said discharge end portion and extending diametrically outward of said discharge end portion, said rear end portion having an annular cavity formed therein which opens toward the rear of said body means, the forward portion of said control means being disposed within said cavity when the control means is in neutral position, said cavity being at least partially arcuate in cross-sectional configuration for reversing the gaseous flow induced between the outer surface of said discharge end portion and the inner surface of said control means during operation of the device, the diametrically inner portion of said trailing edge being beveled, the beveled surface being substantially aligned with the rearward portion of the inner surface of said discharge end portion which defines said nozzle opening when said control means is in neutral position whereby a gaseous jet issuing from said nozzle produces a force tending to bias said control means into neutral position.

4. A device as defined in claim 3 wherein said control means is substantially annular in configuration, the inner surface of said control means defining a segment of a sphere.

5. A device as defined in claim 4 wherein said control means is pivotally supported on said body means by gimbal means whereby said control means may be actuated in a universal manner.

6. A device as defined in claim 3 wherein said control means comprises two elongated members having a longitudinal sectional configuration of a catenary, each of said elongated members encompassing substantially one-half of said discharge end portion, said elongated members being connected for simultaneous movement.

No references cited. 

